P0443 Diagnostic and Fix for 2001 GMC Yukon - Circuit Issue After Purge Valve Replacement
I recently replaced the purge valve on my 2001 GMC Yukon. After resetting the check engine light, it came back on a few hours later. I've already had it diagnosed at AutoZone, which confirmed the issue was related to the purge valve. However, the problem persists after replacement. Could this be due to a wiring or circuit fault? The OBD2 code P0443 indicates a malfunction in the evaporative emission control system circuit. I'm seeking advice on how to properly diagnose and resolve this issue, especially since AutoZone only accessed codes without performing full diagnostics. Any insights into possible causes or next steps would be greatly appreciated.
My 2¢ — First, AutoZone clerks are not technicians; their primary goal is to sell parts. They don't perform full diagnostics — they only access trouble codes. Codes do not automatically mean a part failure. I'm guessing this vehicle has a 5.3L engine? For proper diagnosis of P0443: 1) Check for 12 volts at the wiring connector's pink wire (this is typically the signal wire for the purge valve). 2) Confirm continuity and proper grounding. 3) Use an OBD2 scanner to verify code persistence after clearing. Reference: https://www.obd-codes.com/p0440-p0443